Device for shoring or spragging



May 20, 1941. W. sYLvEsTr-:R 2,242,951

DEVICE FOR SHORING OR SPRAGGING Filed Aug. 14, 1939 Patented May 20, 1941 DEVICE FOR, SHORING 0R SPRAGGING Walter Sylvester, Tunstall, England Application August 14, 1939, Serial No. 289,953 In Great Britain August 15, 1938 7 Claims.

This invention relates to a device for shoring or spragging, for use for example in mines.

The object of the invention is 'an improved device adapted to be attached to .a pit prop or other form of roof support that may be availlable or for use on its own.

According to the invention the improved device comprises a post having at least one step, adapted to lreceive the butt of a sprag.

In a preferred embodiment of the invention the post is provided with means for securing it to a pit prop and is of channel section. The steps to receive the butt of the sprag may be fixed or it may consist o-f an adjustable step adapted to be engaged with xed steps on the post.

In the accompanying drawing- Fig. 1 is a front elevation of one evample of a device-made in accordance with the invention;

Fig. 2 is a section on line 2 2 of Fig. 1,

Fig. 3 is a plan of Fig. 1.

Fig. 4 is a side elevation of Fig. 1.

Fig. 5 is a side elevation of a modilied form ofthe invention,

Fig. 6 is a plan of Fig. 5.

As illustrated in Figs. 1 to 4 the improved device comprises a post I of channel section adapted to be placed against the flange of an H section prop 2 (see Fig. 3) and having at its upper and lower ends means for xing it securely to the prop. The means at the lower end of the post comprises a pair vof side plates 3, welded to the post and adapted to engage the edges of the ange of the prop so as to locate the post against lateral displacement. At the upper end the fixing means comprises at one side a fixed claw 4 adapted to Ice hooked over the flange of the prop and at the other side a lever 5, one part of which is adapted to lbe engaged behind the other flange (see Fig. 3) and the other part of which acts both as a handle and :as a weight to hold the lever in such engaged position (see Fig. 1). The lever 5 is pivoted in a bracket 5a welded to the side of the post. 'I'he engaging lever has a bevel 6 giving a wedging action to grip the ang-e securely.

At its lower end the flanges of the channel are turned inwardly at 1 and such lower part may be lled with wood 8. The object of this construction is to give greater security and to protect the post lagainst undue damage as it may -be subjected to rough use by impact of the coal cutter or other apparatus.

Above such lower `part a series of fixed steps 9 are welded between the flanges, each step having a lip III at its outer end and being weld-ed to the sides and to the bottom of the channel. The outer end of each step is supported by a riser II welded thereto and also similarly welded in the channel. For additional stiiness, such riser may be of arched shape with legs I2 and a cross piece I3 as shown for the uppermost riser in Figs. 1 and 4. In the process of welding, particular attention will be directed to building up a secure support on the riser which will be re- Vquired to support the weight on the sprag. The step and riser `could be formed as a single L shaped 'member which could be fitted with its .angle welded to the back o-f the lchannel and tted so that thefupper part forms a strut below the outer edge of the step above it.

In use the post is easily and quickly secured to the roof prop by hooking its claw 4 on to the flange thereof bringing the side plates 3 into position embracing the flange and then operating the lever 5 to lift it and then lower it behind the flange of the prop. The sprag may then be fitted in known manner, using any of the several steps, whichever may be the most convenient. The post itself rests on the oor and may have a foot of its own of any suitable type and construction.

In a modification of the invention as shown in Figs. 5 and 6 the post Ill still Iof channel section is formed with outwardly turned flanges I5 at its upper part. Welded tothe bottom of the channel at its upper 'part are a number of smaller step pieces I6 whilst a sliding step I'I for the yIcutt of the sprag is provided, having at its upper end hooks or lugs I8 to engage behind the fianges of the post. At its lower end, such slidable step has a toe I9 ladapted to be engaged with the step pieces I6 .at the back of the channel. The upper end of the sliding step is formed as a socket 20 to receive the butt 2I of a sprag. The side flanges I5 will :be inwardly turned at their lower ends as shown in Figs. 1 to 4. 'I'he step pieces I6 are not the full width of the channel and at the upper end yof the sliding step is xed a bridge piece 22, the ends of which engage the back of the channel and can pass the ends of the step pieces I6.

In an alternative construction the side iianges I5 are inwardly turned for their full length and the sliding step modie'd accordingly.

The modified form of the device is otherwise constructed in the same way as the first described example for its attachment to a pit prop.

In use when the post has been secured to the prop the adjustable step is set in the required position and the spragV is then fitted in known manner. The adjustable step is preferably shaped to form a socket for the butt of the sprag.

The bridge piece 22 at the upper part of the slidable step provides support against the bottom of the channel, on each side of the step pieces, so as to take any inward thrust on the bottom of the channel and not on the bent flange.

Obviously, either form of the device could be |adapted for Xing to pit props of other than H section steel props, the back of the device being suitably shaped at or round and for wood props they may have claws to penetrate the wood to prevent their displacement. The device may alternatively be fixed to the prop by chain or other suitable means. Also the device could be placed against a back wall and suitably located therein and used to x a sprag where'there is no convenient pit prop or other roof support structure to which it could be attached.

What I claim is:

1. A devicefor shoring or spragging in mines comprising a channel-shaped post having a plurality of fixed steps arranged in the channel fand each adapted to receive the butt of'a spr'ag.

2. A device for shoring or spragging in mines comprising a channel-shaped post having a plurality of inclined xed steps arranged in the channel and projecting beyond the sides of the same and each provided at its outer edge with a lip Vso that the steps are adapted to receive and locate the butt of a sprag.

3. A device for shoring or spragging in mines comprising a channel-shaped post having a plurality of inclined Xed steps arranged in the channel and projecting beyond the sides of the same and each provided at its outer edge with a lip so that the steps are adapted to receive and locate the butt of a sprag, the steps being provided at the upper part of the post Whilst the sides of the channel at the lower part are inwardly turned.

4. A device for shoring or sprag'ging in mines according to claim 3 wherein a wooden. lling is provided in the lower part of the post between the inturned flanges.

5. A device for shoring or spragging in mines comprising a post having at least one step adapted to receive the butt of a sprag and having means for seciuing it to a pit prop, said means comprising positioning means at the lower end Y of the post and clamping means at the upper end of the post, the clamping means comprising a fixed claw on one side adapted. to engage behind the flange of a girder prop and a pivoted claw at'the other side adapted to be moved behind the ange, the two claws forming a clamping to embrace the flange between them.

6. A device for snoring or spragging in mines comprising a channel-shaped post having a plurality of xed steps arranged in the channel and a step adapted to receive the butt of a sprag, slidably mounted on the channel and having a toe adapted to be engaged with any one of the fixed steps 7. A device according to claim 6 wherein the sides of the channel are outwardly flanged and wherein the sliding step is mounted on such flanges.

WALTER SYLVESTER. 

